Help needed in some basic C++ questions

[NareshShroff]

Hi,
can anyone tell me the answers for the following:

1. Diff. between Class and structures w.r.t memory
I know there is one diff. with access specifiers. But memory wise wat is the difference?
I thought all data members will be stored adjacently in memory in both classes and structs. I know there is diff. b/n union and struct in memory wise.

2. Can u call the following function declaration as overloaded
int fun(char, char) , void fun(int, char)

does it matter with the return types?

Thank You,
NareshShroff

[akpraveen]

2. Can u call the following function declaration as overloaded
int fun(char, char) , void fun(int, char)

I am not sure about the first question, but the 2nd question\'s answer is simple!

The function declaration is different (In Java, you would say that the method signature is different)..

An overload is pretty much using the same function declaration but with different function definition ( meaning, logic is different!)... I am rusty on C++ but with respect to Object Oriented Programming, this is a perfect example of polymorphism (meaning multiple forms/ways to do a thing)! Your return types do not matter when you are doing overloading!

The first question kindles me a little. The difference in memory usage of Classes and Structures is that structures are less memory intensive and heap is allocated during runtime. With classes, memory is allocated during compile time itself.

Good luck!

[priyaraji]

.You can use structure the same way as you use class except for difference with access specifiers.But mostly structures are used to group data and classes are used mostly to group data and functions.
2.Yes the functions given
int fun(char, char) , void fun(int, char) are overloaded.
For instance you may have:

Example of Function Overloading

int area(int s) // For Square
{
return(s*s);
}
float area(float x,float y) // For rectangle
{
return(x*y);
}

double area(double a,double b) // For Triangle
{
return(0.5*a*b);
}


This will have declaration as
float area(float,float);
doble area(double,int);

So as per the above example I have given,your example of function declaration is also a function overloaded

Sripriya

[svs_aditya]

Hi NareshShroff,
Good question..
yes,That is indeed the only difference.
class has 'private',
and struct has 'public'. That's why you'll typicalyl see
derived classes declared as:

class B : public A

So, I suggest using
the different keywords 'class' and 'struct' as
indicators of your intentions: I.e. use 'class'
when you're creating abstract types with special
functionality (e.g. polymorphism), use 'struct'
if simply grouping related simple data items (e.g.
a pair of integer objects). But ultimately, the
choice is yours .
Objects created from a 'struct' definition are no
less than those created from a 'class' definition.

regards,
Aditya